What is the lowest temperature that a substance can reach

The vaporization of 1 mole of liquid water (system) at 100.9 C, 1.00 atm, is endothermic.

yan [13]

Answer:

a) The work done is 10.0777 kJ

b) The water's change in internal energy is -122.1973 kJ

Explanation:

Given data:

1 mol of liquid water

T₁ = temperature = 100.9°C

P = pressure = 1 atm

Endothermic reaction

T₂ = temperature = 100°C

1 mol of water vapor

VL = volume of liquid water = 18.8 mL = 0.0188 L

VG = volume of water vapor = 30.62 L

3.25 moles of liquid water vaporizes

Q = heat added to the system = -40.7 kJ

Questions: a) Calculate the work done on or by the system, W = ?

b) Calculate the water's change in internal energy, ΔU = ?

Heat for 3.25 moles:

$Q_{1} =3.25*(-40.7)=-132.275kJ$

The work done:

$W=-nP*delta(V)=-3.25*101.33*(0.0188-30.62)=10077.6637J=10.0777kJ$

The change in internal energy:

$delt(U)=W+Q_{1} =10.0777-132.275=-122.1973kJ$

7 0

4 years ago

Which of the following elements has the largest electronegativity? A) Bismuth B) Nitrogen C) Potassium D) Arsenic

algol [13]

Hey :)

The answer is B) Nitrogen, which has an electronegativity of 3.04

Hope this helps!

6 0

3 years ago

1. Show that heat flows spontaneously from high temperature to low temperature in any isolated system (hint: use entropy change

Inga [223]

Answer:

1 ) Δs ( entropy change for hot block ) = - Q / th ( -ve shows heat lost to cold block )

Δs ( entropy change for cold block ) = Q / tc

∴ Total Δs = ΔSc + ΔSh

= Q/tc - Q/th

2) ΔSdecomposition = Δh / Temp = ( 181.6 * 10^3 / 773 ) = 234.928 J/k

Explanation:

<u>1) To show that heat flows spontaneously from high temperature to low temperature </u>

example :

Pick two(2) solid metal blocks with varying temperatures ( i.e. one solid block is hot and the other solid block is cold )

Place both blocks for time (t ) in an insulated system to reduce heat loss or gain to or from the environment

Check the temperature of both blocks after time ( t ) it will be observed that both blocks will have same temperature after time t ( first law of thermodynamics )

Δs ( entropy change for hot block ) = - Q / th ( -ve shows heat lost to cold block )

Δs ( entropy change for cold block ) = Q / tc

∴ Total Δs = ΔSc + ΔSh

= Q/tc - Q/th

<u>2) Entropy change for Decomposition of mercuric oxide </u>

2HgO (s) → 2Hg(l) + O₂ (g)

Δs = positive

there is transition from solid to liquid and the melting point of mercury ( the point at which reaction will take place ) = 500⁰C

hence ΔSdecomposition = S⁻ Hg - S⁻ HgO =

Δh of reaction = 181.6 KJ

Temp = 500 + 273 = 773 k

hence ΔSdecomposition = Δh / Temp = ( 181.6 * 10^3 / 773 ) = 234.928 J/k

8 0

3 years ago

If a object has a mass of 10 kilograms, how much does it weigh in newtons?

Len [333]

Depends on where the object is. On earth, moon , or somewhere without any other mass (theoretically). I think you mean how much does weigh on earth. So, the average gravitational acceleration on earth is : 9.83 m/s^2 To find out how much an object weighs, this is the formula : G=m.g where m is mass of the object g is the gravitational acceleration and G is weight. So, G = 10.9,83 = 98,3 N is the answer.

5 0

3 years ago

Which of the answer choices correctly describes a solvent made of molecules that have areas of partial positive and negative cha

damaskus [11]

Answer: polar solvent

Explanation:

Polarity can be said to mean, charge separation. Thus, polar solvents are solvents that have charge separation and the ability to solvate i.e dissolve ions.

A polar solvent molecule has slight electrical charge as a result of its shape. A typical and most common example is water, with an oxygen and two hydrogen atoms. The two hydrogen atoms are at an angle to the single oxygen atom. Water is the classic polar solvent. The oxygen atom tends to polarize electron density to itself.

6 0

3 years ago